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The purpose of this study is to determine if cryopreservation at the blastocyst stage followed by embryo thaw and transfer is as effective as cryopreservation of bipronuclear oocytes followed by post-thaw extended culture (PTEC), and blastocyst transfer. Effectiveness will be measured by the rate of ongoing pregnancy at 10 weeks gestation.

Subjects will be randomized to one of two study groups during their cycles of in vitro fertilization (IVF). In one group, the subjects will have all of their embryos cryopreserved at the blastocyst stage, followed by thaw and transfer in a subsequent cycle. In the other group, subjects will have all of their embryos cryopreserved at the bipronuclear oocyte stage, followed by thaw, extended culture, and transfer in a subsequent cycle.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Any condition that, in the opinion of the physician or principal investigator, would place the patient at undue risk under this protocol or would otherwise make the protocol inappropriate for that subject.